Motorized radio search tuner

ABSTRACT

Radio receiving apparatus having an adjustable search tuner operable over a predetermined band of frequencies, and drive means for moving the tuner at a relatively slow rate for search tuning in one direction of travel, and at a relatively rapid rate for repositioning in the opposite direction. The drive means comprises a tuner drive shaft, a unidirectionally rotatable motor, a lever, and first and second solenoid means coupled with the lever, each selectively energizable to rock the lever in one or the other direction. First and second drive wheel means of different diameters are driven by the motor, and a pair of spaced idler wheels are mounted for rotation on the lever. A first one of the idler wheels is in driven engagement with the larger diameter drive wheel means and the second one of the idler wheels is in driven engagement with the lesser diameter drive wheel means. Energization of the first solenoid means rocks the lever in one direction to engage the second idler wheel with the tuner drive shaft and effect slow drive of the tuner drive shaft. Energization of the second solenoid means rocks the lever in the other direction to engage the first idler wheel with the tuner drive shaft and effect rapid drive of the tuner drive shaft.

[ Dec. 3, 1974 57 ABSTRACT Radio receiving apparatus having an adjustable search tuner operable over a predetermined band of frequencies, and drive means for moving the tuner at a rela- MOTORIZED RADIO SEARCH TUNER Inventors: Howard A. Kell, Jr.; Eugene W.

Yeager, both of Lansdale, Pa.; Allen A. Manteghian, SaoPaulo, Brazil United States Patent [191. Kell, Jr. et al.

tively slow rate for search tuning in one direction of and at a relatively rapid rate for repositioning opposite direction. The drive means comprises a tuner drive shaft, a unidirectionally rotatable motor, a

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ever, and first and second solenoid means coupled with the lever, each selectively energizable to rock the 74/1035, lever in one or the other direction. First and second 334/25. drive wheel means of different diameters are driven by the motor, and a pair of spaced idler wheels are 23, 24, 25; mounted for rotation on the lever. A first one of the 10-5, 10-85 idler wheels is in driven engagement with the larger diameter drive wheel means and'the second one of the idler wheels is in driven engagement with the lesser diameter drive wheel means. Energization of the first solenoid means rocks the lever in one direction to en- 325/471, 334/23 [51] Int. H03j 1/08, H03j 1/12 [58] Field of Search............. 334/19, 20,

[56] References Cited UNlTED STATES PATENTS gagethe second idler wheel with the tuner drive shaft and effect slow drive of the tuner drive shaft. Energization of the second solenoid means rocks the lever in Schwarz..,....... Gaskill et al....

Schwarz ct al..

Andrews.........

Clark .llllll the other direction to engage the first idler wheel with the tuner drive shaft and effect rapid drive of the tuner drive shaft.

11 Claims, 5 Drawing Figures PrimaryExaminer-Paul L. Gensler Attorney, Agent, or Firm-Robert D. Sanborn; Harry W. Hargis, lIl

MOTORIZED RADIO SEARCH TUNER BACKGROUND OF THE INVENTION This invention relates to radio tuning apparatus, and more particularly to improved means for driving a radio search tuner at a relatively slow rate for searching in one direction, and for driving the tuner at a relatively rapid rate for repositioning in the opposite direction.

One well known apparatus of the foregoing type comprises an automobile radio receiver of the kind incorporating a so-called stop-on-signal search tuning system. In such a system, a tuning carriage is caused to move automatically, upon initiation by an operator, to search for a strong radio signal in a particular area. Upon receiving such a signal, the tuning carriage will be halted in its travel, consequently tuning-in the station. Should the'tuning carriage reach the end of the tuning band without a station having been located, the tuning carriage will be automatically returned, at a relatively rapid rate, to the opposite end of the tuning band where it will stand repositioned for an ensuing search operation.

It is ageneral objective of the present invention to provide an improved search-tune drive mechanism featured by simplicity of construction and by capability of ready assembly with tuning mechanism of otherwise conventional construction.

SUMMARY OF THE INVENTION 5 In achievement of the foregoing as well as other objectives and advantages, the invention contemplates the provision, in radio receiving apparatus having adjustable means for tuning over a predetermined band of frequencies, of improved drive means for moving said tuning means at a relatively slow rate in one direction of travel for search tuning and at a relatively rapid rate in the opposite direction for repositioning, which drive means comprises: a unidirectionally rotatable motor;a

pair of drive wheel means, of different diameters,

driven by said motor; a lever; a first and second solenoid means coupled with said lever, each selectively energizable to move said lever in one or the other direction; first andsecond spaced idler wheels mounted for rotation on said-lever, said first idler wheel being disposed in driven engagement with the drive wheel means of larger diameter, said second idler wheel being I disposed in driven engagement with the drive wheel best be achieved and will be more fully understood from a consideration of the following description taken in light of the accompanying drawing.

y BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective showing of radio receiver apparatus including a tuner drive embodying the invention;

FIG. 2 is a partially exploded, perspective view of the apparatus seen in FIG. 1, but on a larger scale and with portions fragmented or removed for convenience of illustration of elements of the tuner drive; FIG. 3 is an elevational showing of the right hand portion of the apparatus seen in FIG. 2, looking generally in the direction of the axis of pivot P, and showing an operational feature of the invention;

FIG. 4 is 'a view similar to FIG. 3, and illustrating a further operational feature of the invention; and

FIG. 5 is a diagrammatic showing of electrical control circuitry associated with the tuner and its drive.

DESCRIPTION OF THE PREFERRED EMBODIMENT With more detailed reference to the drawing,.and first to FIGS. 1 and 2, a radio receiver includes a frame structure designated generally by the numeral 1 1 and which supports slides 12 actuatable, by pushbutton 12a, between the illustrated extended position and a retracted operative position.

With more detailed reference to FIG. 2, a treadle bar 13 is operable by a slide 12, only one of which is shown for convenience of illustration. Treadle bar 13 is rotatable about pivots 14 on frame structure 11 conveniently formed from sheet metal of suitable thickness to ensure its rigidity. A cam 15 is provided on each of slides 12, and is positioned operably to engage treadle bar 13 upon movement of a slide to retracted position, in response to manual pressure on a pushbutton 12a. Each of slides 12 is returned to and held in its extended position by suitable spring means'(not shown) of conventional design.

A core carriage 16 is mounted in-slots 16a, 16b on frame 11 for sliding movements in the direction of movement of the pushbutton slides 12. Carriage l6 is vmoved by treadlebar 13 through linkage means including pin-and-slot interconnections 17, 18 between the core carrage and treadle bar. Coil cores, one of which is seen at 20, are affixed to carriage 16 by suitable known means, so that the cores extend into coil forms 21 disposed in core shield means 21a, in the direction of movement of carriage 16. The cores 20 together with coils wound about 'coil forms 21 comprise variable permeability tuning elements for an AM broadcast band receiver. A pointer L operable, in known manner, by carriage 16 is movable across dial M (FIG. 1) in upscale and down-scale directions.

In addition to drive by slides 12 and their associated earns 15, treadle bar 13 is capable also of being driven by a tuner drive shaft 22 through a spur gear 23 on the shaft meshed with a sector gear 24 on treadle bar 13.

'One mode of rotating tuner drive shaft 22 is by a manual knob and shaft assembly 25 provided with a spur gear 26 meshed with a crown gear 27 coupled with tuner drive shaft 22 through a clutch 31 of conventional design, and operable to declutch the manual assembly upon operation of a pushbutton slide 12. In achievement of declutching, each slide 12 is so constructed that upon its movement to retracted position,

it cammingly engages and pivots a rotatable declutching bar 32 provided with an edge-cam 29. A lever is linked to the operating plate of clutch 31 and is operable by edge-cam 29 to declutch tuner drive shaft 22 from crown gear 27 upon operating of a slide 12.

In particular accordance with the invention, and with reference also to FIGS. 3 and 4, the end of tuner drive shaft 22 extending beyond clutch 31 is provided with a friction wheel 33. A lever 35 is pivoted on frame portion lla about a pivot P having an axis extending generally parallel to the axis of wheel 33. A pair of solenoids 36 and 37 are coupled with the lever 35, through springs 41, 42, and are selectively energizable to rock lever 35 in one direction (L.H. arrow, FIG. 3) or the other direction (RH. arrow, FIG. 4) about its pivot P. First and second drive wheel means 43 and 44 are concentrically journalled for rotation on frame 1 1a and are driven by a unidirectionally rotatable motor 45 through a worm 46 and worm gear teeth 47 on wheel means 43. A pair of idler wheels 48 and 49 are mounted for rotation on lever 35, about parallel axes disposed to opposite sides of pivot P of the lever. Idler wheel 48 includes a gear portion 48a continuously meshed with a flanged inner gear portion 43a of larger drive wheel means 43, and a friction tire portion 48b disposed in the plane of tuner wheel 33. Idler wheel 49- includes a gear portion 490 continuously meshed with a gear portion 44a of small wheel 44, and a friction tire portion 49b disposed in the plane of tuner wheel 33.

Wheel means 43, 44, idler wheels 48, 49, tuner wheel 33, and lever 35 are so cooperably disposed that when lever 35 is rocked in one direction (left hand arrow, FIG. 3) from its rest, or neutral, position as shown in FIG. 2, tire portion 49b of idler wheel 49 is moved into frictional driving engagement with tuner wheel 33 in provision of low speed tuning drive, and when lever 35 is rocked in the other direction (right hand arrow, FIG. 4) tire portion 48a of idler wheel 48 is moved into frictional driving engagement with tuner wheel 33 in provision of high speed repositioning. Neutral position of lever 35 is maintained by opposed coil springs 38, 39, connected between frame 11a and an arm on lever 35 as is best seen in FIG. 2.

Further to the showings in FIG. 2, 3, and 4, anelectrically grounded limit switch arm 51 is affixed to tuner shaft 22 for rotation therewith. The tuner shaft 22 and switch arm 51 are rotatable through an angle of about 270 in the course of full scale tuning, i.e., movement of pointer L from one end of the dial M to the other (FIG. 1). Switch arm 51 is electrically engageable, at either end of its rotational travel, with a corresponding one of switch contacts 52 and 53 carried by and insulated from frame Ila.

With reference also to FIG. 5, clutch lever 30 is actuatable, in the search tuning mode to be described below, by plunger 54a of a solenoid 54 linked thereto through a pin-and-slot connection designated generally by the numeral 55 (FIG. 2). In provision of the searchtuning mode of operation, one terminal of battery B is connected to a suitable ground, for example the frame of an automobile, and its other terminal is connected in series electrical circuit with a pushbutton switch 56, a relay switch 57, and one terminal of a relay coil 58, the other terminal of which is grounded. A normallyopen relay switch 59 operated by relay coil 58 is disposed in parallel electrical circuit with pushbutton switch 56. Also connected in series electrical circuit with battery B is a second normally-open relay switch 60 operated by coil 58, and one terminal of drive motor 45, the other terminal of which is grounded. Clutch solenoid 54 is disposed in parallel electrical circuit with motor 45. A third normally-open relay switch 61 operated by coil 58 is connected to the receiver in known manner to serve as a muting switch. A station detector,

A Power Flip Flop of conventional design has its inputs electrically connected to switch contacts 52 and 53 as shown, and its outputs are electrically connected,

also as shown, to lever actuating solenoids 36 and 37 having a common ground terminal.

In operati or rof the apparatus thus far described, and assuming that it is desired to tune to the next strong signal upscale, manually operable switch 56 is closed momentarily by an operator, energizing relay coil 58 from battery B through normally closed relay switch 57. Energization of relay coil 58 closes normally-open switches 59, 60, and 61. Closure of switch 59 maintains energization, i.e., locks in, relay coil 58, and closure of switch 60 energizes motor and clutch solenoid 54, the latter operation disengaging manual tuning knob and shaft assembly 25. Closure of switch 61 mutes the receiver. At the time of closure of switch 56, limitswitch arm 51 will be in the region intermediate contacts 52 and 53, and the Power Flip Flop will be conditioned to energize tuning solenoid 36. As described hereinabove, and as seen in FIG. 3, energization of solenoid 36 rocks lever 35 in a left-hand direction urging tire portion 49b of the rotating slow-speed idler wheel 49 into driving engagement with tuner friction drive wheel 33. As wheel 33 is driven, the tuner is operated up-scale until such time the Station Detector senses a strong signal, and operates to energize relay coil 62 and open relay switch 57. Opening of switch 57 de-energizes relay coil 58, thereby opening switches 59, 60, and 61. Opening of switch de-energizes drive motor 45, accompanied .by de-energization of clutch solenoid 54, which de-energization of the motor halts the tuner at the strong detected signal. The apparatus is then ready for its next search tuning operation, or it may be tuned manually, since de-energization of solenoids 36 and 37 permits centering springs 38 and 39 to hold lever 35 in its neutral position.

Assuming, however, a condition under which no strong signal has been detected, motor 45 will continue to drive the tuner at search-tuning speed until switch arm 51 engages switch contact 52. Engagement of arm 51 with contact 52 conditions the Power Flip Flop to de-energize solenoid 36 and energize solenoid 37, thereby rocking lever 35 in a right-hand direction (FIG. 4) to engage tire portion 48b of rotating idler wheel 48 with tuner drive wheel 33, in provision of high speed repositioning of the tuner in a downscale direction. Full repositioning of the tuner is accompanied by engagement of switch arm 51 with contact 53, whereby Power Flip Flop is conditioned to de-energize solenoid 37 and again energize solenoid 36 to rock lever 35 to the search-tuning position shown in FIG. 3. The motor 45 will then continue to operate in provision of the searchtuning mode as hereinabove described.

From the foregoing, it will be appreciated that the invention affords an improved search-tune drive mechanism featured by simplicity of construction and by capability of ready assembly with tuning mechanism of known design. While the invention has been disclosed in connection with an automotive AM receiver, it will be understood that it has utility also in connection with automotive AM-FM receivers.

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1. in radio receiving apparatus of the type including adjustable means for tuning over a predetermined band of frequencies, improved drive means for moving said tuning means at a relatively slow rate for tuning in one direction of travel and at a relatively rapid rate for re positioning in the opposite direction, said drive means comprising: a unidirectionally rotatable motor; a lever; first and second solenoid means coupled with said lever, each selectively energizable to rock said lever in one or the other direction; first and second drive wheel means, of different diameters, driven by said motor;v

and a pair of idler wheels on said lever, one idler wheel being driven by said first drive wheel means of larger diameter, the other idler wheel being driven by said second drive wheel means of lesser diameter, said lever being operable to move said other idler wheel into driving engagement with the tuning means, to provide a relatively slow drive coupling between said first drive wheel means and said tuning means, upon energization of said first solenoid means to rock said lever in one direction, and said lever being operable to move said one idler wheel into driving engagement with the tuning means, to provide a relatively rapid drive coupling be tween said second drive wheel means and said tuning means, upon energization of said second solenoid means to rock said lever in the other direction.

2. Drive means according to claim], and characterized in that said tuning means includes wheel means selectively engageable by said idler wheels to effect the recited movement of said tuning means.

3. Drive means according to claim 2, and further characterized by the inclusion of a worm driven by said motor, and a worm gear concentric with and coupled to said first and second drive wheel means, said worm gear being drivingly meshed with said worm, and in that said first and second drive wheel means are journalled for concentric rotation.

4. Drive means according to claim 1, and characterized in that said first and second drive wheel means are journalled for concentric rotation, and further in that said first drive wheel means includes a peripheral flange, said one idler wheel being continuously drivingly engaged with the radially inwardly facing surface of said peripheral flange, and also in that said other v idler wheel is continuously drivingly engaged with said second drive wheel means.

5. Drive means according to claim 4 and furthe characterized in that the recited driving engagements of said idler wheels with said first and second drive wheel means comprise meshed gear teeth provided on respective ones of the idler wheels and drive wheel means.

6. Drive means according to claim 5, and further characterized by the inclusion of a worm driven by said motor, anda worm gear on the radially outwardly facing surface of said peripheral flange on said first drive wheel means, said worm being drivingly meshed with said worm gearin provision of the recited drive of said first and second drive wheel means by said motor.

7. For use with radio receiving apparatus of the type including adjustable means for tuning over a predetermined band of frequencies, improved drive means for moving such a tuning means at a relatively slow rate for tuning in one direction of travel and at a relatively rapid rate for repositioning in the opposite direction, said drive means comprising: a unidirectionally rotatable motor; a lever; first and second solenoid means coupled with said lever, each selectively energizable to rock said lever in one or the other direction; first and second drive wheel means, of different diameters,

driven with said motor; and a pair of idler wheels on said lever, one idler wheel being driven by said first drive wheel means of larger diameter, the other idler wheel being driven by said second drive wheel means of lesser diameter, said lever being operable to move said other idler wheel into driving engagement with such tuning means, to provide a relatively slow drive coupling between said first drive wheel means and the tuning means, upon energization of said first solenoid means to rock said lever in one direction, and said lever being operable to move said one idler wheel into driving engagement with such tuning means, to provide a relatively rapid drive coupling between said second drive wheel means and the tuning means, upon energization of said'second solenoid means to rock said lever in the other direction.

8. Drive means according to claim 7, and characterized in that said first and second drive wheel means are journalled for concentric rotation, and further in that said first drive wheel means includes a peripheral flange, said one idler wheel being continuously drivingly engaged with the radially inwardly facing surface of said peripheral flange, and also in that said other idler wheel is continuously drivingly engaged with said second drive wheel means.

9. Drive means according to claim 8 and further characterized in that the recited driving engagements of said idler wheels with said first and second drive wheel means comprise meshed gear teeth provided on respective ones of the idler wheels and drive wheel means.

10. Drive means according to claim 9, and further characterized by the inclusion of a worm driven by said motor, and a worm gear on the radially outwardly facing surface of said peripheral flange on said first drive wheel .means, said worm being drivingly meshed with said worm gear in provision of the recited drive of said first and second drive wheel means by said motor.

11. Drive means according to claim 7, and further characterized by the inclusion of limit switch means operable to effect alternate energization and deenergization of said first and second solenoid means in provision of the recited fast and slow drive couplings. 

1. In radio receiving apparatus of the type including adjustable means for tuning over a predetermined band of frequencies, improved drive means for moving said tuning means at a relatively slow rate for tuning in one direction of travel and at a relatively rapid rate for Repositioning in the opposite direction, said drive means comprising: a unidirectionally rotatable motor; a lever; first and second solenoid means coupled with said lever, each selectively energizable to rock said lever in one or the other direction; first and second drive wheel means, of different diameters, driven by said motor; and a pair of idler wheels on said lever, one idler wheel being driven by said first drive wheel means of larger diameter, the other idler wheel being driven by said second drive wheel means of lesser diameter, said lever being operable to move said other idler wheel into driving engagement with the tuning means, to provide a relatively slow drive coupling between said first drive wheel means and said tuning means, upon energization of said first solenoid means to rock said lever in one direction, and said lever being operable to move said one idler wheel into driving engagement with the tuning means, to provide a relatively rapid drive coupling between said second drive wheel means and said tuning means, upon energization of said second solenoid means to rock said lever in the other direction.
 2. Drive means according to claim 1, and characterized in that said tuning means includes wheel means selectively engageable by said idler wheels to effect the recited movement of said tuning means.
 3. Drive means according to claim 2, and further characterized by the inclusion of a worm driven by said motor, and a worm gear concentric with and coupled to said first and second drive wheel means, said worm gear being drivingly meshed with said worm, and in that said first and second drive wheel means are journalled for concentric rotation.
 4. Drive means according to claim 1, and characterized in that said first and second drive wheel means are journalled for concentric rotation, and further in that said first drive wheel means includes a peripheral flange, said one idler wheel being continuously drivingly engaged with the radially inwardly facing surface of said peripheral flange, and also in that said other idler wheel is continuously drivingly engaged with said second drive wheel means.
 5. Drive means according to claim 4 and further characterized in that the recited driving engagements of said idler wheels with said first and second drive wheel means comprise meshed gear teeth provided on respective ones of the idler wheels and drive wheel means.
 6. Drive means according to claim 5, and further characterized by the inclusion of a worm driven by said motor, and a worm gear on the radially outwardly facing surface of said peripheral flange on said first drive wheel means, said worm being drivingly meshed with said worm gear in provision of the recited drive of said first and second drive wheel means by said motor.
 7. For use with radio receiving apparatus of the type including adjustable means for tuning over a predetermined band of frequencies, improved drive means for moving such a tuning means at a relatively slow rate for tuning in one direction of travel and at a relatively rapid rate for repositioning in the opposite direction, said drive means comprising: a unidirectionally rotatable motor; a lever; first and second solenoid means coupled with said lever, each selectively energizable to rock said lever in one or the other direction; first and second drive wheel means, of different diameters, driven with said motor; and a pair of idler wheels on said lever, one idler wheel being driven by said first drive wheel means of larger diameter, the other idler wheel being driven by said second drive wheel means of lesser diameter, said lever being operable to move said other idler wheel into driving engagement with such tuning means, to provide a relatively slow drive coupling between said first drive wheel means and the tuning means, upon energization of said first solenoid means to rock said lever in one direction, and said lever being operable to move said one idler wheel into driving engagement with such tuning means, to provide a relatively rapid drivE coupling between said second drive wheel means and the tuning means, upon energization of said second solenoid means to rock said lever in the other direction.
 8. Drive means according to claim 7, and characterized in that said first and second drive wheel means are journalled for concentric rotation, and further in that said first drive wheel means includes a peripheral flange, said one idler wheel being continuously drivingly engaged with the radially inwardly facing surface of said peripheral flange, and also in that said other idler wheel is continuously drivingly engaged with said second drive wheel means.
 9. Drive means according to claim 8 and further characterized in that the recited driving engagements of said idler wheels with said first and second drive wheel means comprise meshed gear teeth provided on respective ones of the idler wheels and drive wheel means.
 10. Drive means according to claim 9, and further characterized by the inclusion of a worm driven by said motor, and a worm gear on the radially outwardly facing surface of said peripheral flange on said first drive wheel means, said worm being drivingly meshed with said worm gear in provision of the recited drive of said first and second drive wheel means by said motor.
 11. Drive means according to claim 7, and further characterized by the inclusion of limit switch means operable to effect alternate energization and de-energization of said first and second solenoid means in provision of the recited fast and slow drive couplings. 